//
//
// Copyright 2017 gRPC authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
//

#ifndef GRPC_SRC_CORE_LIB_SURFACE_VALIDATE_METADATA_H
#define GRPC_SRC_CORE_LIB_SURFACE_VALIDATE_METADATA_H

#include <stdint.h>

#include <cstring>

#include "absl/log/check.h"
#include "absl/strings/string_view.h"

#include <grpc/slice.h>
#include <grpc/support/port_platform.h>

#include "src/core/lib/iomgr/error.h"

namespace grpc_core {

enum class ValidateMetadataResult : uint8_t {
  kOk,
  kCannotBeZeroLength,
  kTooLong,
  kIllegalHeaderKey,
  kIllegalHeaderValue
};

const char* ValidateMetadataResultToString(ValidateMetadataResult result);

// Returns nullopt if the key is legal, otherwise returns an error message.
ValidateMetadataResult ValidateHeaderKeyIsLegal(absl::string_view key);

}  // namespace grpc_core

grpc_error_handle grpc_validate_header_key_is_legal(const grpc_slice& slice);
grpc_error_handle grpc_validate_header_nonbin_value_is_legal(
    const grpc_slice& slice);

int grpc_is_binary_header_internal(const grpc_slice& slice);
inline int grpc_key_is_binary_header(const uint8_t* buf, size_t length) {
  if (length < 5) return 0;
  return 0 == memcmp(buf + length - 4, "-bin", 4);
}
inline int grpc_is_refcounted_slice_binary_header(const grpc_slice& slice) {
  DCHECK_NE(slice.refcount, nullptr);
  return grpc_key_is_binary_header(slice.data.refcounted.bytes,
                                   slice.data.refcounted.length);
}

#endif  // GRPC_SRC_CORE_LIB_SURFACE_VALIDATE_METADATA_H
